Traffic signal



Dec; 26, 1933. R WORRALL 1,940,831

TRAFFIC SIGNAL Filed July 11, 1931 INVENTOR I RoberZ 1i VVarraZZ ATTORNEY Patented Dec. 26, 1933 UNITED STATES PATENT OFFICE 1,940,831 'rnArrro SIGNAL Robert H. Worrall, Washington, D. 0.

Application July 11, 1931.

3 Claims. (01. 171-339) act of March 3, 1883, as 0, 1928; 3700. G. 157) The invention relates to method of and apparatus warning in which a tion on either road ing until the car has section.

(Granted under the amended April 3 car arriving by interrupting improvements in the for cross roads trafllc at an interseca beam of flash in both directions inue the waminter- An object of this invention is provide a method for warning tersection on one of on the other road.

Another object of 0 a relay cutting road and cause a a driver approaching an intwo intersecting roads that another machine is approaching the intersection this invention is to provide apparatus for the practice of my method.

According to my invent ordinarily be exposed to tr on, a green light will afiic approaching the ds in both directions. A intersection will trip the other rections on the other intersecting road. This flashing of the red for the machine 5 upon the the green drawing.

should all be in the respective locations. 7 and 8 should tive lights on discontinuance light will be turned The circuits accomplishing showing diagrammatically in the be located opposite the proper side of the road for center of Light trafllc approaching the intersection.

Light sensitive cell 5 is in ser 9 and relay 13. Light sens with battery 10 and relay 14.

the same. the road at their sensitive cells 5, 6, their respece ht will continue long enough to clear the intersection and of the flashing red light on again.

these results are accompanying Reference numbers 1, 2, 3 and 4 are sources of light with current supply for These ies with battery itive cell 6 is in series Light sensitive cell '7 is in series with battery 11 and relay 15. Light sensitive cell 8 is in relay 16.

The control circuits are: a 0 battery 1'1, soleno'd of 18, and

5 15 and 13 associated series with battery 12 and ircuit comprising front contacts of with road east-west, E-W;

of 14 and with road north-south, N-S.

0 battery 21, right battery 21, one of prising battery 22,

19, solenoid of 16, associated The lighting circuits are; a circuit comprising contact of 18 and lights G, or the left contacts of 18, approand a circuit comt of 20 and lights G, or battery 22, one of the right contacts of 20,

5 appropriate jumpers Mandiights R.

capacity would cause Serial No. 550,122

The operation of this invention is as follows: Normally both control circuits are energized, holding the arms of 18 and 20 on the contacts which are not connected by jumpers to the other contacts, and lighting lights G and G.

The interruption of the beam from source 1 by a car will open relay l3, deenergize the solenoid of 18 and allow a spring to draw the arm of 18 to the extreme left. As the car passes on, the relay 13 will be closed again and the solenoid of l8 energized, drawing the arm of 18 to the right which because of the dash pot will be a slow motion. When the arm of 18 was moved to the left the lights G were cut oil and lights R lighted. As the arm of 18 moves slowly to the right it will cut ofi the red light while it is on the insulation between contacts but through the jumpers will light it again when the arm reaches the next contact. The result is that lights R areflashed on and off as the arm moves to the right and upon reaching the last contact the lights R are cut of! and the lights G are lighted. The flashing red lights R show in both directions on the N-,-S

road. The same operation would result from the inso terruption of the beam from 3 by a car approaching from the east. Since the beams of light are across only the right side of each approach, but one beam of light will be interrupted by a car passing straight across the intersection or on en- 5 tering the intersection and then turning either left or right.

In a similar manner a car either direction on the N-S road will cause the lights G to be cut off and the lights R to be flashed until the car is clear of the intersection, when light G will be lighted again.

If cars approaching approximately simultaneously on the N-S and the E-W road, the lights R as well as the lights R' will be flashed. But the beams of light may be placed far enough from the intersection to give both cars ample time to stop before reaching the intersection and so avoid a collision. They can then proceed through the intersection in accordance with the customary traflic rules. I 1 It is clear tha the relays 13,14, 15 and 16 could be operated by a number of different means, such as through the medium of a vacuum tube bridge I circuit, where a change in capacity would cause a current to flow operating the relay; or an oscillating vacuum tube circuit where a change in the circuit to oscillate and ting the relay. The success-' 1m approaching from current to flow opera 111 operation of my invention does not depend upon the means employed for this purpose.

While in the foregoing there has been illustrated and described such'combination and arrangement of elements as constitutes the preferred embodiment of this invention, it is nevertheless desired to emphasize the fact that interpretation of the invention should be conclusive only when made in the light of subjoined claims.

The herein described invention may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

I claim:

1. In a traffic signaling system for intersecting highways, a go indication and a stop indication for each highway, a movable switch arm for one highway, a second movable switch arm for the second highway, a plurality of segments for each switch arm over which the switch arm is adapted to pass in contact and normally resting on one of said segments, means normally inactive for each highway, operable for a predetermined time when actuated for moving a switch arm for that highway from rest position over its associated segments, means in one highway for connecting said indicating means to a switch arm and associated segments to display the go indication to the other highway when the switch arm is at rest and for intermittently displaying the stop indication to that highway when the switch arm is moving, means for the other highway similar to the second named means, and vehicle actuated means in each highway for actuating the first named means for the corresponding highway.

2. In a trafiic signaling system for intersecting highways, a go signal and a stop signal for each highway, traflic actuated devices for each approach to an intersection, a switch arm individual to each highway, spring means for actuating said arm to move it in one direction, electromagnetic means for moving said arm in the other direction against said spring, a source of potential, normally closed contacts connecting said source of potential in circuit with said electromagnetic means, means comprising said traiflc actuated devices for opening said normally closed contacts responsive to traflic actuation whereby said electromagnetic means de-energizes and permits said spring means to move said switch arm, a plurality of contacts associated with said switch arm for flashing the stop signal of the intersecting highway as said arm moves there-across responsive to the energization of the magnetic means, and means comprising another contact associated with said switch arm for actuating the go signal of the intersecting highway when the magnetic means is energized and said switch arm is returned to said other contact.

3. In a traific warning system for two intersecting highways, a go" signal and a stop signal for each highway, vehicle actuated electrical devices for each approach to the intersection, a movable switch arm for each highway, a plurality of contacts associated with each said switch arm so disposed that a terminal one of said contacts is in circuit with the go signal for the intersecting highway and the remainder are in circuit with the stop signal for that highway, an electromagnetic means associated with each switch arm so operated by said vehicle actuated electrical devices that said switch arms are held on or being returned to said terminal contacts when no tramc is passing, spring means for moving said switch arms across the remainder of contacts when said electromagnetic means are deenergized responsive to actuation of vehicle actuated electrical devices, and means connecting the vehicle actuated electrical devices and movable switch arm of one highway with the stop? and go signals of the other highway.

ROBERT H. WORRALL. 

